Axios

Around 190 unexplained cases of severe hepatitis have been reported in children in at least a dozen countries, the European Centre for Disease Prevention and Control announced on Tuesday.

Driving the news: Last week, the CDC reported that there were nine cases of hepatitis in children between the ages of 1 and 6.

Russian President Vladimir Putin struck a defiant tone in a televised meeting with António Guterres Tuesday, showing little interest in the UN secretary-general's proposal for a UN role in helping civilians flee the war in Ukraine.

The big picture: Guterres said that while "we believe that there was an invasion into the territory of Ukraine," he "arrived in Moscow with a pragmatic approach." Guterres, who will visit Kyiv later this week, said his "main task" was to improve the humanitarian situation.

Russia's seizure of the Chernobyl nuclear power plant was "absolutely abnormal and very, very dangerous," Rafael Grossi, director general of the International Atomic Energy Agency (IAEA), said Tuesday during his visit to the plant, according to the New York Times.

Why it matters: The power plant, which is inoperative but still manages the fallout of the 1986 nuclear disaster and stores and processes nuclear waste, fell under Russian control in the first day of its invasion of Ukraine.

An unusually intense spring heat wave is bringing blistering heat to large portions of Pakistan and India, with the potential for monthly records for April to fall this week in some areas.

Why it matters: Millions in this heavily populated region lack access to air conditioning, and could suffer from heat-related illnesses, which can be deadly. In addition, the heat will make outdoor work untenable for portions of the day, slowing construction projects and impacting the economy.

Robert Santos, the first Latino director of the U.S. Census Bureau, says he wants to remedy the severe undercount of Hispanics by returning to old-school ways, including more door-to-door contact.

Why it matters: The undercount of Latinos in the 2020 census was three times higher than in 2010. Many Black and Native Americans were also omitted from the population tally.

The UN voted unanimously on Tuesday to adopt a rule that would automatically trigger a General Assembly meeting if any of the Security Council's five veto-wielding members use that power to block a resolution.

Driving the news: The measure is meant to put more scrutiny on Russia, which has a history of using its veto power to unilaterally stop Security Council resolutions. Russia earlier this year vetoed a measure aimed at stopping its invasion of Ukraine.

The EU on Tuesday said that Twitter must "quickly adapt" to its rules on content moderation after Elon Musk, who has been vocal about freedom of speech on the platform, agreed to buy the company for $44 billion.

What they're saying: "Be it cars or social media, any company operating in Europe needs to comply with our rules — regardless of their shareholding," Thierry Breton, the EU's internal market commissioner, tweeted. "Mr Musk knows this well."

Wimbledon said Tuesday that it won't have a COVID-19 vaccination requirement for this year's tournament, clearing the way for Novak Djokovic to defend his title in London.

Driving the news: Djokovic wasn't allowed to play in the Australian Open in January because he wasn't vaccinated for COVID-19 and received a three-year visa ban from Australia.

U.S. Secretary of Defense Lloyd Austin said Tuesday that Western countries will "keep moving heaven and earth" to help Ukraine defend against Russia's unprovoked invasion.

Why it matters: Austin and Joint Chiefs chairman Mark Milley held a meeting with more than 30 defense officials from dozens of NATO and non-NATO countries at Ramstein Air Base in Germany to coordinate military aid for Ukraine as Russia's invasion shifts to an offensive against the country's Donbas region.

Germany's minister of defense, Christine Lambrecht, said Tuesday her country will deliver an unspecified number of anti-aircraft tanks to Ukraine.

Why it matters: The announcement comes amid mounting pressure on the German government to increase military aid to Ukraine in response to Russia's unprovoked invasion.

Secretary of State Antony Blinken, in his first public appearance since returning from Kyiv, will be questioned by members of the Senate Foreign Relations Committee on Tuesday morning about the Biden administration's response to the war in Ukraine.

Why it matters: Blinken is expected to shed more light on the administration's plans to send American diplomats back to Ukraine this week, as well as President Biden's decision to nominate Bridget Brink, the current U.S. ambassador to Slovakia, to fill the ambassadorial post in Kyiv that’s been vacant since 2019, a senior State Department official tells Axios.

Russia's top diplomat said in a TV interview with state media late Monday that NATO "in essence, is engaged in a war with Russia through a proxy and is arming that proxy."

The big picture: Russian Foreign Minister Sergey Lavrov also warned against provoking a third world war and said the threat of a nuclear conflict "should not be underestimated," according to a transcript from Russia's Foreign Ministry.

Satellite imagery has detected another mass grave outside Mariupol, the besieged strategic port city in southeast Ukraine that has been bombarded by Russian forces for weeks, Radio Free Europe first reported on Monday.

Driving the news: The third mass grave site detected by U.S. firm Planet Labs' satellite imagery around Mariupol was captured from March 24 to April 24 in the Russian-occupied village of Staryi Krym, some five miles from the city, according to dates on the images and local officials.

Jeff Bezos on Tuesday questioned Elon Musk's business interests in China in light of his billionaire space rival's Twitter bid.

Driving the news: Some commentators have raised concerns of potential Chinese government interference if Musk owned Twitter, given he has a Tesla factory in China. Bezos responded to one of these points on Twitter, raised by New York Times journalist Mike Forsythe's post:

• Representatives for Musk did not immediately respond to Axios' request for comment.